Described herein are aspects generally related to communication systems, and more particularly, to allocating resources is wireless communications.
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of a telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, further improvements in LTE technology may be desired. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
In LTE, there are three types of downlink resource allocation supported for allocating resources to a user equipment (UE): one allocation type (type 2) is based on virtually contiguous resource allocation with one resource block (RB) granularity; another allocation type (type 0) is based on RB groups (RBG) where each RBG includes a number of consecutive RBs based on the system bandwidth and a bitmap indicates sets of RBGs assigned to a UE; and another allocation type (type 1) is based on RBG subsets that may be shifted. In type 1 allocation, three fields can be communicated to the UE including a first field with ceiling(log 2(P)) bits used to indicate a selected RBG subset among RBG subsets (e.g., 2 bits for 20 megahertz (MHz)), a second field with one bit used to indicate a shift of the resource allocation span within a subset, and a third field used to indicate a bitmap where each bit addresses a single virtual RB in the selected RBG subset such that the most significant bit to least significant bit of the bitmap are mapped to the virtual RBs in increasing frequency order.
In wireless communication systems employing legacy LTE, a plurality of UEs served by a particular eNodeB may be scheduled resources for communicating with the eNodeB over one or more channels using transmission time intervals (TTI) on the order of a 1 millisecond subframe. As UE capabilities and demand for bandwidth increases, lower latency in communications may be desired.